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Particular Conditions (particular + condition)
Selected AbstractsInflammation alters somatostatin mRNA expression in sensory neurons in the ratEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 1 2005Seham A. Abd El-Aleem Abstract Proinflammatory neuropeptides, such as substance P and calcitonin gene-related peptide, are up-regulated in primary afferent neurons in acute and chronic inflammation. While these neuropeptides have been intensively studied, potentially anti-inflammatory and/or anti-nociceptive neuropeptides such as somatostatin (SS) have been less widely investigated. Endogenous somatostatin is thought to exert a tonic antinociceptive effect. Exogenous SS is anti-inflammatory and antinociceptive and is thought to exert these actions through inhibition of proinflammatory neuropeptide release. In this study we have compared the expression of somatostatin in two inflammatory models: arthritis, a condition associated with increased nociception, and periodontitis, in which there is little evidence of altered nociceptive thresholds. In acute arthritis (< 24 h) SS mRNA was down-regulated in ipsilateral dorsal root ganglia (DRG; 52 ± 7% of control, P < 0.05), and up-regulated in contralateral DRG (134 ± 10% of control; P < 0.05). In chronic arthritis (14 days) this pattern of mRNA regulation was reversed, with SS being up-regulated ipsilaterally and down-regulated contralaterally. In chronic mandibular periodontitis (7,10 days), SS mRNA was up-regulated in only the mandibular division of the ipsilateral trigeminal ganglion (TG) (day 7, 219 ± 9% and day 10, 217 ± 12% of control; P < 0.02) but showed no change in other divisions of the trigeminal ganglion or in the mesencephalic nucleus. These data show that antinociceptive and anti-inflammatory neuropeptides are also regulated in inflammation. It is possible that the degree of inflammation and nociception seen may depend on the balance of pro- and anti-inflammatory and nociceptive peptide expression in a particular condition. [source] Astrocytes in the hippocampus of patients with temporal lobe epilepsy display changes in potassium conductancesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2000Stefan Hinterkeuser Abstract Functional properties of astrocytes were investigated with the patch-clamp technique in acute hippocampal brain slices obtained from surgical specimens of patients suffering from pharmaco-resistant temporal lobe epilepsy (TLE). In patients with significant neuronal cell loss, i.e. Ammon's horn sclerosis, the glial current patterns resembled properties characteristic of immature astrocytes in the murine or rat hippocampus. Depolarizing voltage steps activated delayed rectifier and transient K+ currents as well as tetrodotoxin-sensitive Na+ currents in all astrocytes analysed in the sclerotic human tissue. Hyperpolarizing voltages elicited inward rectifier currents that inactivated at membrane potentials negative to -130 mV. Comparative recordings were performed in astrocytes from patients with lesion-associated TLE that lacked significant histopathological hippocampal alterations. These cells displayed stronger inward rectification. To obtain a quantitative measure, current densities were calculated and the ratio of inward to outward K+ conductances was determined. Both values were significantly smaller in astrocytes from the sclerotic group compared with lesion-associated TLE. During normal development of rodent brain, astroglial inward rectification gradually increases. It thus appears reasonable to suggest that astrocytes in human sclerotic tissue return to an immature current pattern. Reduced astroglial inward rectification in conjunction with seizure-induced shrinkage of the extracellular space may lead to impaired spatial K+ buffering. This will result in stronger and prolonged depolarization of glial cells and neurons in response to activity-dependent K+ release, and may thus contribute to seizure generation in this particular condition of human TLE. [source] Esophageal Causes of Sudden and Unexpected DeathJOURNAL OF FORENSIC SCIENCES, Issue 2 2006Roger W. Byard M.D. ABSTRACT: Gastrointestinal conditions are uncommon causes of sudden and/or unexpected death as compared to cardiovascular diseases, motor vehicle trauma, or suicide, and may involve an array of fatal mechanisms. Lethal esophageal conditions are encountered even less often, the manifestations of which include acute upper airway occlusion from tumors or foreign material, intraluminal hemorrhage from vascular abnormalities, or perforation with fistula formation resulting in hemorrhage and sepsis. When encountered at autopsy, a particular condition may also be a manifestation of a disease that does not primarily involve the esophagus. For this reason, a detailed autopsy investigation is required for evidence of systemic or remote disease when lesions are found within the esophagus. In this report, possible life-threatening esophageal conditions are reviewed with a description of lethal mechanisms, mention of rare associated diseases, and comment on difficulties that may arise at autopsy in the evaluation of such cases. [source] Evaluation of Repatriation Parameters: Does Medical History Matter?JOURNAL OF TRAVEL MEDICINE, Issue 1 2009Sjoerd Greuters MD Background Aeromedical repatriation of patients is an expanding service due to the growing number of travelers worldwide. Of these repatriated patients, a small number require specialized transportation due to severe medical complications. We evaluated the medical in-flight records of Dutch patients with severe disease or polytrauma who were repatriated by air from 1998 to 2002 via one of the largest Dutch alarm centers. We questioned how this Dutch population of repatriated patients is demographically distributed and whether this population is a priori at high risk for acute medical complications that need specialized medical attention. Results Seventy-seven of 115 repatriated patients were 50 years and older, of which most were male (73%). Fifty patients had no significant medical history, whereas the remaining 65 patients suffered from comorbidities such as cardiovascular disease or cancer. In patients aged 18 to 49 years, one third of all patients were repatriated due to traumatic fractures. In the older age category, the main reasons for repatriation were cardiopulmonary incidents. There was an equal distribution in the primary medical reason for repatriation as defined by need for trauma/neurological support and ventilation or circulatory support. Of note, 82% of the 65 patients who traveled with a chronic disease condition were repatriated due to worsening of this particular condition. Conclusions The present study shows that an aeromedical repatriation service is frequently employed by travelers with a history of chronic disease who develop medical complications. The growing number of repatriated elderly patients and/or patients with preexisting comorbidities requires development of secure pretravel risk assessment and adaptation of the medical service level in foreign countries. [source] Group IID heparin-binding secretory phospholipase A2 is expressed in human colon carcinoma cells and human mast cells and up-regulated in mouse inflammatory tissuesFEBS JOURNAL, Issue 11 2002Makoto Murakami Group IID secretory phospholipase A2 (sPLA2 -IID), a heparin-binding sPLA2 that is closely related to sPLA2 -IIA, augments stimulus-induced cellular arachidonate release in a manner similar to sPLA2 -IIA. Here we identified the residues of sPLA2 -IID that are responsible for heparanoid binding, are and therefore essential for cellular function. Mutating four cationic residues in the C-terminal portion of sPLA2 -IID resulted in abolition of its ability to associate with cell surface heparan sulfate and to enhance stimulus-induced delayed arachidonate release, cyclooxygenase-2 induction, and prostaglandin generation in 293 cell transfectants. As compared with several other group II subfamily sPLA2s, which were equally active on A23187- and IL-1-primed cellular membranes, sPLA2 -IID showed apparent preference for A23187-primed membranes. Several human colon carcinoma cell lines expressed sPLA2 -IID and sPLA2 -X constitutively, the former of which was negatively regulated by IL-1. sPLA2 -IID, but not other sPLA2 isozymes, was expressed in human cord blood-derived mast cells. The expression of sPLA2 -IID was significantly altered in several tissues of mice with experimental inflammation. These results indicate that sPLA2 -IID may be involved in inflammation in cell- and tissue-specific manners under particular conditions. [source] Structural heterogeneity and productivity of a tall fescue pasture grazed rotationally by cattle at four stocking densitiesGRASSLAND SCIENCE, Issue 1 2008Maria Silvia Cid Abstract The spatial heterogeneity in the structure and the productivity of the vegetation was examined in a tall fescue (Festuca arundinacea Schreb.) pasture rotationally grazed at four stocking densities in the Pampean region of Argentina. The examined pasture was grazed at the stocking densities of 3.6, 4.6, 5.6 and 6.6 animals ha,1 with a two-paddock 14-day rotational grazing system. Spatial distribution of plant height was examined as well as the percentages of short patch area (heavily utilized patches) or tall patch area (areas ungrazed or lightly defoliated). In addition, biomass, growth rate and relative growth rate were assessed for both short and tall patches. Grazing generated patchiness in vegetation structure and growth at all stocking densities. Increased stocking density caused an increase in the percentage of the short patch area in the paddocks. Short patches had relatively less live biomass than tall ones, but their relative growth rate was 31% higher than that of tall patches (0.021 ± 0.007 vs 0.016 ± 0.005 g DM g DM,1 day,1). The increase in stocking density enlarged the proportion of short patch areas with higher relative growth rate. The relative growth rate (average between short and tall patches) of the two highest stocking densities was 61.7% higher than that of the low stocking density treatments (0.023 ± 0.006 vs 0.014 ± 0.004 g DM g DM,1 day,1). Although the growth rate of the short patches did not exceed the value of the tall patches, the high value of relative growth rate appeared to indicate a higher photosynthetic capacity of the short patches. Moreover, live biomass did not decrease during the experimental period even in the short patch areas showing that, in the particular conditions of our study, overgrazing did not occur at the range of the stocking density examined. [source] Review and comparison between the Wells,Riley and dose-response approaches to risk assessment of infectious respiratory diseasesINDOOR AIR, Issue 1 2010G. N. Sze To Abstract, Infection risk assessment is very useful in understanding the transmission dynamics of infectious diseases and in predicting the risk of these diseases to the public. Quantitative infection risk assessment can provide quantitative analysis of disease transmission and the effectiveness of infection control measures. The Wells,Riley model has been extensively used for quantitative infection risk assessment of respiratory infectious diseases in indoor premises. Some newer studies have also proposed the use of dose-response models for such purpose. This study reviews and compares these two approaches to infection risk assessment of respiratory infectious diseases. The Wells,Riley model allows quick assessment and does not require interspecies extrapolation of infectivity. Dose-response models can consider other disease transmission routes in addition to airborne route and can calculate the infectious source strength of an outbreak in terms of the quantity of the pathogen rather than a hypothetical unit. Spatial distribution of airborne pathogens is one of the most important factors in infection risk assessment of respiratory disease. Respiratory deposition of aerosol induces heterogeneous infectivity of intake pathogens and randomness on the intake dose, which are not being well accounted for in current risk models. Some suggestions for further development of the risk assessment models are proposed. Practical Implications This review article summarizes the strengths and limitations of the Wells,Riley and the dose-response models for risk assessment of respiratory diseases. Even with many efforts by various investigators to develop and modify the risk assessment models, some limitations still persist. This review serves as a reference for further development of infection risk assessment models of respiratory diseases. The Wells,Riley model and dose-response model offer specific advantages. Risk assessors can select the approach that is suitable to their particular conditions to perform risk assessment. [source] Video tracking system optimization using evolution strategiesINTERNATIONAL JOURNAL OF IMAGING SYSTEMS AND TECHNOLOGY, Issue 2 2007Jesús García Abstract A video-based tracking system for airport surveillance, composed by modules performing vision tasks at different levels, is adapted for operational conditions by means of Evolution Strategies (ES). An optimization procedure has been carried out considering different scenes composed of representative trajectories, supported by a global evaluation metric proposed to quantify the system performance. The generalization problem (the search of appropriate solutions for general situations, avoiding over-adaptation to particular conditions) is approached considering evaluation of ES-individuals over combinations of trajectories to build the fitness function. In this way, the optimization procedure covers sets of trajectories representing different types of problems. Besides, alternative operators for aggregating partial evaluations have been analysed. Results show how the optimization strategy provides a sensitive tuning of performance related to input parameters at different levels, and how the combination of different situations improves the generalization capability of the trained system. The global performance final system after optimization is also compared with representative algorithms in the state of the art of visual tracking. © 2007 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 17, 75,90, 2007 [source] Evaluation of numerical simulation methods in reactive extrusionADVANCES IN POLYMER TECHNOLOGY, Issue 3 2005Linjie Zhu Abstract Reactive extrusion is a complex process, and numerical simulation is an important method in optimizing operational parameters. In the current work, two different simulation methods, one-dimensional (1D) model and three-dimensional (3D) model, were introduced to predict the polymerization of ,-caprolactone in fully filled screw elements. The predicted results of polymerization progression under different simulation conditions based on these two methods were compared. The simulation results show that the simplifications and assumptions in 1D model make it difficult to capture the complex mixing mechanism, heat generation, and heat loss in reactive extrusion. 1D model is feasible only under particular conditions, such as low screw rotating speed, small heat from reaction, and small screw diameter, whereas 3D model is a more powerful simulation tool for much wider processing conditions. © 2005 Wiley Periodicals, Inc. Adv Polym Techn 24: 183,193, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20041 [source] The Governance of Networks and Economic Power: The Nature and Impact of Subcontracting RelationshipsJOURNAL OF ECONOMIC SURVEYS, Issue 5 2003Silvia Sacchetti Abstract., Current debate on networking focuses on network structures and firm strategies. In this perspective, theoretical analysis has been concerned with allocative issues. This essay proposes a different interpretation. Starting from the existing theoretical framework, we emphasise the nature and the implications of different types of networks with respect to socio-economic development from a distributional point of view. Within this context, we develop the analysis of subcontracting starting from the concept of economic power. We then provide an analysis of governance in production by considering the attitudes and the nature of the actors involved. The externalisation of activities by large transnationals, which characterises current corporate restructuring, is often related to the search for greater flexibility, but also for greater power over governments, labour, and subcontractors. Differently, networks based on the mutual dependence of actors, which are not necessarily built around a large firm, could , under particular conditions , reach large production scales or more complex scopes without breaking the links with territorial systems, thus including local objectives in the strategic decision-making process. Our conclusion is that the impact of subcontracting networks varies enormously. This is crucial to an understanding of future trends and possibilities. Not least, firms and public policy agencies need to understand the implications of different forms of subcontracting network and how those forms actually differ in practice. [source] American College of Radiology Appropriateness CriteriaJOURNAL OF THE AMERICAN ACADEMY OF NURSE PRACTITIONERS, Issue 7 2001APRN-C, Mary Jo Goolsby EdD The Clinical Practice Guideline (CPG) series provides an overview of one CPG each month. The overview includes a brief summary of the guideline's content, as well as the identification of some factors by which the author has critiqued it. The first article in the series reviewed the steps of CPG critique. Subsequent columns have described CPGs related to viral upper respiratory illnesses, tobacco dependence, menopause and perimenopause, and musculoskeletal evaluation. The document described in this month's clinical practice guideline column is actually a set of recommendations ranking the appropriateness of specific radiologie imaging or therapeutic options for particular conditions or presentations. The American College of Radiology Appropriateness Criteria provides a very valuable resource when ordering diagnostic imaging procedures. [source] Helium implantation into 4H-SiCPHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 8 2009Jean François Barbot Abstract The paper provides the properties of single crystalline 4H-SiC under helium implantation at temperatures of implantation up to 750,°C and fluences in the range 5,×,1015,1,×,1017,cm,2. The microstructure evolution was studied by transmission electron microscopy cross-section and X-ray diffraction experiments. The mechanical property changes were investigated by using nanoindentation tests followed by atomic force microscopy observations and by using tribological tests. At elevated temperature of implantation and/or in the low fluence regime at room temperature where only the strained state of SiC is obtained, SiC becomes more resistant to crack formation but no significant change in mechanical properties is seen. At room temperature with increasing fluence the damage accumulation leads to the amorphous state for which a strong degradation of the mechanical properties is observed. At elevated temperature of implantation, amorphization is avoided and a thermally activated saturation of the strain is observed in the near surface region whereas defect accumulation occurs near the maximum of damage. Upon annealing subsequent to room temperature implantation, the near surface strain progressively relaxes while the helium ions agglomerate into platelets around the maximum of strain. These platelets evolve into bubble clusters at temperatures where the vacancies become mobile. Under particular conditions of implantation (high fluence and elevated temperature) the swelling of the surface increases during annealing due to the growth of bubbles and the formation of stacking faults resulting from the migration of interstitials towards the maximum of damage. [source] Growth and mortality of common octopus Octopus vulgaris reared at different stocking densities in Mediterranean offshore cagesAQUACULTURE RESEARCH, Issue 10 2009Benjamín García García Abstract Four ongrowing cycles of common octopus (Octopus vulgaris), each with two stocking densities, were carried out in an offshore area in order to evaluate the effect of the following variables on growth (G, % body weight day,1) and mortality (M, % day,1): weight (W, 0.5,3.0 kg), temperature (T, 14,26 °C), stocking density (SD, 6,46 kg m,3), size dispersion, expressed as coefficient of variation (CV, 13,42%) and significant wave height (SWH: 0.4,1.2 m). The assays were performed in an 8 m3 stainless-steel floating cage divided into two compartments of 4 m3 each. For the range of temperatures considered (14,26 °C), G depended significantly on T and SWH, with maximum G values being obtained at 18.5 °C and with an important negative effect of SWH. M depended significantly on T, W and CV, mortality being minimal at 18 °C. The two other variables had an antagonistic effect, mortality increasing with greater size dispersion , suggesting that animals should be graded throughout the process , although the effect diminished as the sizes increased. The results point towards two alternatives for the commercial ongrowing of octopus under the particular conditions of the present study: (A) two ongrowing cycles of 3.5 months to reach a final weight of 2.5 kg or (B) one 5-month cycle to reach a final weight of 3.5 kg. [source] The Child Health Questionnaire in Australia: reliability, validity and population meansAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 2 2000Elizabeth Waters Objective: To provide reliability, validity and population means for the Australian Authorised Adaptation of the parent-report Child Health Questionnaire (CHQ). Method: We surveyed a representative sample of Australian parents of school-aged children (5,18 years) in Victoria between July and December 1997, using a school-based cluster sample design stratified by educational sector and age. Results: Some 5, 414 parents responded (72%). Good psychometric performance was observed for the CHQ in Australia. Population means demonstrated differences in health on domains of functioning and well-being by age and gender. This population-derived sample demonstrated high ceiling values on Physical Functioning and Social Role scales. Implications: The CHQ appears to be a reliable and valid measure of child and adolescent functional health and well-being for the Australian population. Child health outcomes of children and adolescents with particular conditions or within population subgroups can be compared with these age and gender benchmarks. Appropriate uses for the CHQ may be to discriminate between children who are generally healthy and children with health problems, or in population surveys partnered with measures that extend the range of physical functioning and social functioning. [source] Trophic-dynamic considerations in relating species diversity to ecosystem resilienceBIOLOGICAL REVIEWS, Issue 3 2000KRIS H. JOHNSON ABSTRACT Complexity in the networks of interactions among and between the living and abiotic components forming ecosystems confounds the ability of ecologists to predict the economic consequences of perturbations such as species deletions in nature. Such uncertainty hampers prudent decision making about where and when to invest most intensively in species conservation programmes. Demystifying ecosystem responses to biodiversity alterations may be best achieved through the study of the interactions allowing biotic communities to compensate internally for population changes in terms of contributing to ecosystem function, or their intrinsic functional redundancy. Because individual organisms are the biologically discrete working components of ecosystems and because environmental changes are perceived at the scale of the individual, a mechanistic understanding of functional redundancy will hinge upon understanding how individuals' behaviours influence population dynamics in the complex community setting. Here, I use analytical and graphical modelling to construct a conceptual framework for predicting the conditions under which varying degrees of interspecific functional redundancy can be found in dynamic ecosystems. The framework is founded on principles related to food web successional theory, which provides some evolutionary insights for mechanistically linking functional roles of discrete, interacting organisms with the dynamics of ecosystems because energy is the currency both for ecological fitness and for food web commerce. Net productivity is considered the most contextually relevant ecosystem process variable because of its socioeconomic significance and because it ultimately subsumes all biological processes and interactions. Redundancy relative to productivity is suggested to manifest most directly as compensatory niche shifts among adaptive foragers in exploitation ecosystems, facilitating coexistence and enhancing ecosystem recovery after disturbances which alter species' relative abundances, such as extinctions. The framework further explicates how resource scarcity and environmental stochasticity may constitute ,ecosystem legacies' influencing the emergence of redundancy by shaping the background conditions for foraging behaviour evolution and, consequently, the prevalence of compensatory interactions. Because it generates experimentally testable predictions for a priori hypothesis testing about when and where varying degrees of functional redundancy are likely to be found in food webs, the framework may be useful for advancing toward the reliable knowledge of biodiversity and ecosystem function relations necessary for prudent prioritization of conservation programmes. The theory presented here introduces explanation of how increasing diversity can have a negative influence on ecosystem sustainability by altering the environment for biotic interactions - and there by changing functional compensability among biota - under particular conditions. [source] | |||||||||||||||||||